Known 2/2- or 3/2-way valves comprise an intake channel and one or two outlet channels. In a 2/2-way valve, the intake channel is connected to the sole outlet channel. The outlet channel can be opened or closed by means of an actuator which can be provided, for instance, as a displaceable piston. A 2/2-way valve can also be designed as a controlling valve wherein the position of the actuator will control the size of a passage opening and thus the size of a mass flow passing through the valve. A conventional 3/2-way valve has two outlet channels formed therein, one of these outlet channels normally being closed by an actuator. Further, both of the above types of valves are provided with a drive element connected to the actuator. The drive element, provided e.g. as an electrical drive unit such as a stepping motor, serves for moving the actuator.
Particularly in automobile technology, a requirements exists that valves be switchable by use of small actuating forces so as to allow the use of small-sized and light-weighted drive elements. Further, strict requirements exist with regard to leak-tightness. For an exact regulating and controlling of processes, for instance, leakage caused by valves are disadvantageous. Valves have to be particularly leak-tight when used in connection with fuel cells. In fuel cells, which are normally operated by use of a mixture of hydrogen and oxygen or air, it must be safeguarded that, e.g., no undesired mixing of oxygen and hydrogen occurs because already a hydrogen portion of as little as 3% would result in an explosive hydrogen/oxygen mixture. In known valves, high leak-tightness can be obtained e.g. in that an actuator, formed as a piston, is pressed against a sealing with considerable force.